Abstract : It is the purpose of this analysis to devise a means of theoretically predicting the flow fields induced by hovering rotors in ground effect and influenced by the proximity of a vertical step. A two dimensional investigation is performed. Assuming a perfect fluid allows the problem to be solved using complex potential theory. Values of induced velocities and stream function are determined by considering the contributions of a finite number of discreet vortices and their images in the transformed plane. Results appear to be qualitatively accurate within the confines of the wake cylinder and in areas very close to the wake boundaries. (Author)